With Mobile World Congress 2013 just around the corner, it makes sense that we start hearing about some new phones from Nokia. Up on the list are the Lumia 520 and Lumia 720, expected sequels to the current Lumia 510 and Lumia 710 series but with OS upgrades and more refined specifications.

The news come via recent filing with Indonesia's equivalent to the FCC, lending heavy credence to their existence (that and we are expecting a 710-follow up with Windows Phone 8). The Lumia 720 (RM-885), listed as manufactured in China, could be destined for many markets including T-Mobile US where the Flame was recently outed. Likewise, the Lumia 510 (RM-914) is also listed on the Indonesia filing.

The document does not give any details, but an unknown and evidently non-confirmed source reportedly gave the specifications of both devices to MyNokia Blog. Because of that, we have to take these with an extreme amount of caution, seeing as this could easily be made up. Having said that, let’s not kid ourselves—the 520 and 720 are entry level and mid-range phones, so their features shouldn’t be too extravagant.

The anonymous sources were sure to point out the word "devices," when they said that there would be five of them unveiled at MWC. This denotes that we may see what has been a long-anticipated tablet from the Finnish manufacturer.

I've been eyeing the 720 ever since the 920 and 820 were released. A 4.0" inch, 5:3 screen and 1GB RAM and I'm sold.
I'm doubtful of the specs mentioned. My guess is the 720 and the 520 will just be smaller versions of the 820 and 620.
920 = 4.5", 820 = 4.3", 720 = 4.0", 620 = 3.8", 520 = 3.5". Perfect lineup.

If the 720 gets only 512MB RAM, this puts it firmly in the low-end category together with the 620 and 520.. I was hoping for a 1GB RAM. I would rather that it gets only a 4.0" screen size but a 1GB RAM because this puts it closer to mid-range WP8 devices rather than low-end, and would cluster it in category with the 920 and 820.

Im really looking forward to the 720/Zeal since the 620 hasnt got enough battery time/mah for me (please get the review ready :D). I guess it'll have 1 gig of ram because there wouldnt be a difference besides screen size and design to the 620.

As in Brazil everything arrives late, the 720 and 520 Lumias should be released here at the end of 2013. The Brazil is an important market for low-cost smartphones, where only the Samsung has won with its galaxy line.

720 needed there is an empty space between 620 and 820 some people can afford a phone higher than 620 but don't want to spend more on 820 , 720 will have perfect specification between both remember multiple choices always good for consumers. also that gap between 820 and 620 filled with android phones so there need to be a windows phone to compete in that area

I'm skeptical on the 6MP camera thing, and also the 4.3" screen for the 720.
My guess would be a 720 would ideally be the same processor as the 620, but with more storage, a 4" screen and ideally an option for wireless charging. Its possible for a 4.3" screen, but I am starting to wonder here if the >4" screens are not the best size even (a lot of people are making those sized screens, but maybe we'll see a move back down in size?).
As for the 520, I have no idea, the old 610 used to have 1/2 the memory, not really sure how they can shave any more off the phone short of removing the front camera...

Its definitely good news that they are coming, its also good news in a way that Nokia are still not able to keep up with demand for the 920, they definitely need to have a bumper year this year to get firmly established.

I'm with falcon304. I get that many people like the bigger screens, but for me the 920 is simply too much. I'd pay a premium for the features of a 920 or even 820, but in a 710 or slightly larger form factor. Unfortunately that size phone seems stuck in the lower-mid to low end range.